Zoology Lecture 6

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Zoology Lecture 6
2010-10-19 16:15:24

Zoology Lecture 6
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  1. What and how many kingdoms exist within the domain eukaryota
    • 1. Protozoa
    • 2. Animalia
    • 3. Fungi
    • 4. Plantae
    • 5. Chromista
  2. What is the main difference between protozoa and vertebrets
    The fact that protozoa is dominated by an environment with high viscous forces
  3. Are there advantages to living ina world dominated by inertial forces?
    ANSER THIS he asked it
  4. What is the cost of living in a world with hgiher inertial forces
    takes more energy to do things
  5. What are the limits to size increase and complexity in protozoans
  6. What is the "issue of mass transfer"?
    Issue of mass transfer - movement of matter within a system
  7. What are two general forms of movment associated with a protists environment
    • 1. Diffusion
    • 2. Bulk motion/convection
  8. Does diffusion (above) require energy for movement?
    No it does not. Diffusion is the free energy gradiant
  9. Does bulk motion/convection (above) require energy for motion?
    Yes energy input is required
  10. Do we generally see the above two processes together or acting alone?
    Both of these processes are interlocked and we will gnerally see one process of the two dominating the other.
  11. What is Ficks first law?
    Fick's first law relates the diffusive flux to the concentration field, by postulating that the flux goes from regions of high concentration to regions of low concentration, with a magnitude that is proportional to the concentration gradient (spatial derivative).
  12. Whats flux equal to?
    • Flux = Ja = (-D) x (dC/dx)
    • Where D is the diffusion constant
  13. What is a key restriction on cell size
    The diffusion of mRNA to various parts of the cell limits the size of which a cell can grow to
  14. Whats an example of overcoming the restrictions of smal cell size due to mRNA diffusion
    • create more mRNA sources i.e create more nuclei
    • hence we end up with micro and macro nucleated cells
  15. Whats another solution to the limiting effects of cell size
    forma colony
  16. What are two types of colonies that can form (general)
    Spherical and plate like colonies can form
  17. How was ficks law used to describe or measure the size of a cell
    ficks law the difussion law looked at the diffusion of oxygen into a cell. cells need oxygen. so if the oxygen cant get far enough into the cell the cell will die.
  18. What are Metazoa
    Multicellular, obligatory heterotrophic eukaryotes
  19. How do metazoa first develop
    by mitotic divisions of a zygote formed by fusion of two angiogamates
  20. PORIFERA just saying
  21. What is ment genera;l;y by porifera
    Pore bearers/sponges
  22. Body symmetry ____________ and highly dependant on local _______ ________.
    • 1. plastic
    • 2. ecological conditions.
  23. Multicellular but with a restricted number of ______, no true _____ and with low levels of _________ between cells.
    • cell types
    • tissues
    • coordination
  24. ___________ are characteristic and generate feeding currents.
  25. Define Choanocyte
    • Choanocytes (also known as "collar cells") are cells that line the interior of Asconoid, syconoid and leuconoid body type sponges that contain a central flagellum surrounded by a collar of microvilli which are connected by a thin membrane
    • The flagellae beat regularly, creating a water flow across the microvilli which can then filter nutrients and other food from the water taken from the collar of the sponge. Food particles are then phagocytosed by the cell.
  26. Principal mode of food acquisition – _____________
    filter/suspension feeding
  27. A large dependency on _________ for material exchange.
  28. A sometimes elaborate skeletal system of ________________ (spongin) fibresor a combination of these.
    calcareous or siliceous spiculesor collagen
  29. Adults are _____ but development usually involves a __________ larva.
    • sessile
    • planktonic
  30. Reproduction: . ___________________ The latter may be gonochoristicbut more commonly __________.
    • asexual or sexual
    • hermaphroditic.
  31. Exclusively aquatic and overwhelmingly ______. - ----- WTF
  32. Should we consider a sponge as an organism or more so a colony of cells
    More so a colony of cells because a sponge is at the cellular grade
  33. See figure 4.5 for basic sponge morphology
  34. Define pinacoderm
    pinacoderm - is the outer most layer of cells (pinacocytes) in the phylum Porifera (sponges), equivalent to the epidermis in other organisms.
  35. Define the choanoderm
    Choanoderm - is composed of flagellated collar cells, or choanocytes. The sponge body is mostly a connective tissue, the mesohyl, over which are applied epithelioid monolayers of cells, the outer pinacoderm and the inner choanoderm.
  36. Define porocytes
    Porocytes are tubular cells which make up the pores of a sponge.
  37. Define osculum
    Osculum - a large opening in a sponge through which water flows out of the sponge. Sponges may have more than one oscula.
  38. Define Archeocytes
    Archaeocytes or amoebocytes are amoeboid cells found in sponges. They are totipotent and have varied functions depending on the species. Reside in mesophyll performing various functions
  39. What are scleroblasts
    Scleroblasts - a spicule secreting cell in porifera
  40. What is ment by rhabdiferous cells
    Rhabdiferous cells is the gelatenous stuff that makes up the mesophyll layer of sponges
  41. Do sponges have muscles? if so in what form
    Yes they do. Myocytes acting as sphyncters to entrances
  42. What can spicules be used for?
    Species identification
  43. See figure 4.5 for spicles and body forms :-)
  44. Done